Games I would avoid but might hypothetically recommend to others
If you think about the examples of disturbing content frequently listed in content warnings, there is a subset of elements I definitely do not want to encounter in interactive fiction even while not begrudging people who feel differently. Sometimes it depends on whether the PC is the agent, a passive observer, or a passive participant. In many such cases I would not let my idiosyncrasies prevent me from recommending the work to someone I think might enjoy it, although I would offer to give them a trigger warning.
Games that make me uncomfortable enough that I would not want to share them with others
In my opinion the most egregious examples are games that mislead the player about provocative content, and here it is important to note that this can be done by omission. For example, if the game makes the PC a perpetrator or a victim of rape or “dubious consent” and the author does not so much as label it AIF or horror, then in my opinion that is a huge violation of the author–player contract. If I encounter a game of this sort, I will not recommend it to anyone, not even with the caveat that it is not properly labeled. Similarly, if I am playtesting for an author who has thrust me into the role of telling them that their work is improperly or inadequately labeled, I might bow out politely, but underneath my demeanor I will be seething. (Even “this beta build depicts nonconsensual acts, but I need help figuring out how to label it” is significantly better than nothing.) While appropriate genre labels might be enough to avoid raising my ire, I don’t know why authors wouldn’t use appropriate content warnings in these situations as they are the obvious, unambiguous way to avoid foisting unwelcome surprises on players or playtesters.
I probably would not want to share a game defined by pervasive use of sordid details, especially if they are all of the same character. Such a game would likely leave me feeling disturbed for some time, and if it didn’t, it would have inured me to the details the author wants me to find shocking, and neither of these is a good selling point. Mind you, I think this tends to be less a matter of intention than execution. So I would not begrudge an author who made a work like this; I would just think they chose an unfortunate path while trying to reach their goal.
Speaking of disturbing content, if a game makes suicide a win condition, I will wish I had never played it and will not recommend it to others. And I will not recommend a work that makes shooting the dog the only (obvious) solution to a puzzle, even if only to literally put the dog to sleep. (I’m looking at you, Elysium Enigma.)
Games that make me wonder why anyone would want to play them
I wonder why anyone would want to play games that include the most abhorrent behavior (child abuse, sexual violence, overtly racist acts, etc.) without contextualizing it as immoral or terror-inducing. If I’m consuming satire, I invariably find myself asking, “How long would the target of this satire be able to partake of this before realizing that they are being targeted?” The more time passes, my discomfort grows exponentially. (Thus, while I think Get Out is one of the best horror movies ever made, I find Them, a TV series that tries to be something similar, to be an absolute dumpster fire.) Satirical or not, if a work itself is not enough to tell me that the author disapproves of the awful behavior, I will be perplexed as to why anyone would want to engage with it.